Vehicle and method for controlling a drive unit of the vehicle

Abstract

A vehicle comprises a drive unit operable by muscle power and having an adjustable transmission ratio, a control device for adjusting (IV) the transmission ratio of the drive unit, and a detection device for high-resolution detection of a change in the angle of rotation to determine (III) a rotational speed gradient of at least one wheel of the vehicle. The control device is configured to adjust (IV) the transmission ratio of the drive unit, taking into account a desired operating state and an actual operating state. The control device is configured to adjust (IV) the transmission ratio of the drive unit, taking into account the rotational speed gradient.

Description

Technical FieldThe present invention relates to a vehicle and a method for controlling a drive unit of a vehicle.Prior ArtVehicles having methods for automatically setting a transmission ratio of a drive unit of the vehicle that can be operated at least two times with muscle power are known. The transmission ratio can be automatically set on the basis of a driver's key range that can be selected by a driver. In this case, transmission ratios are set which lead to a very high pedaling force.SUMMARY OF THE INVENTIONIt is an object of the present invention to provide an improved vehicle with which ride comfort can be increased.The object is achieved by a vehicle having the features of claim 1. Advantageous further developments are the subject of the dependent claims.A vehicle comprises a muscle power drive unit having an adjustable gear ratio, a controller and a detector. The control device is configured for the transmission ratio. The detection device is configured for high-resolution detection of a change in the angle of rotation for determining a rotational speed gradient of at least one wheel of the vehicle. The vehicle can be formed by an e-bike or pedelec. The vehicle can be operable at least temporarily with muscle power. The drive unit can have a mechanical drive. The drive unit can have a crank unit with a crank. The drive unit can have an electric drive, for example an electric motor, for supporting the mechanical drive. The drive unit can have a power store for operating the electric drive. The drive unit can have at least one of a sprocket transmission, a toothed belt transmission, a continuously shiftable transmission or a power split transmission to provide a transmission ratio. The drive unit may have a number of gears, each associated with a transmission ratio of the drive unit. A high gear may be associated with a lower gear ratio than a low gear. The control device can be configured to shift gears. Via a gear jump, the transmission ratio can be switched from one gear to the transmission ratio of another gear. The vehicle may have a shift-by-wire shift. The wheel may be a drive wheel. The wheel may be a rear wheel.The control device is configured to set the transmission ratio of the drive unit taking into account a setpoint operating state and an actual operating state. The control device is configured to set the transmission ratio of the drive unit taking into account the rotational speed gradient. The control device can be configured for selected actual operating states of the vehicle for setting the transmission ratio of the drive unit while deviating from the desired operating state.The actual operating state may include, as parameters, at least one of an actual gear ratio, a wheel speed of the wheel, a speed gradient of the wheel, a carcass, a pedal force, a crank torque, a vehicle acceleration, and an inclination of the vehicle. The carcass can be determined at the pedal crank via a rotational speed sensor. The wheel speed and the actual transmission ratio can be determined, for example, by the control device. The pedal force may be determined by a pressure sensor. The pedal force determined can be related to a pedaling force applied by the driver. The crank torque can be determinable by the control device, for example, via the pedal force together with a crank radius of the pedal crank. The crank torque can be determined at the pedal crank unit via a torque sensor, for example a force sensor or strain gauge placed accordingly.The detection device can be configured to detect a portion of a wheel revolution of the wheel. The wheel revolution can occur, for example, during a travel movement of the vehicle. The fraction of a wheel revolution may be a fraction of a complete wheel revolution. The portion of a wheel revolution can be formed by a wheel sector. The portion of a wheel revolution can be associated with an angle of less than 360°, for example less than 180°, for example less than 10°. The portion of a wheel revolution can be associated with an angle of 1°. The angle can be associated with a rotational angle of the wheel, for example. For each portion of a wheel revolution, a change in angle of rotation can be detected. The detection device can be configured to detect the change in the angle of rotation per time. The detection device can be configured to determine a rotational speed for each portion of a wheel revolution. The detection device can be configured to determine a wheel rotational speed based on one or more rotational speeds for one or more portions of a wheel revolution.Ascertaining the wheel rotational speed can be based on the change in rotational angle per time success. The determination of the rotational speed gradient can be effected on the basis of a wheel rotational speed change per time. For a complete wheel revolution, a plurality of rotational speed gradients can be determined. A wheel speed fluctuation can thus also be determined for a complete wheel revolution. This can be made possible by using the detection device which is configured for high-resolution detection of a change in the angle of rotation. With a usual detection device, which is based on the detection of a single pulse per wheel revolution, a rotational speed gradient can be determined only for a complete wheel revolution. The number of determinable rotational speed gradients or the mean values thereof for a wheel revolution can be associated with the number of detectable portions of a wheel revolution. The detection device is configured for high-resolution detection of a change in the angle of rotation in that a plurality of rotational speed gradients or their mean values can be determined during a wheel revolution.The detection unit can be configured such that the change in the angle of rotation is detected at the wheel. The detection unit can be configured such that the detection of the change in the angle of rotation at an element of the drive unit, for example the pedal-type short-cut unit, takes place taking into account an actual transmission ratio of the drive unit.The selected actual operating state can be formed by an actual operating state for which at least one parameter for the actual operating state has a specific value. At least one of a full braking, a slip, a driving into an incline, a driving into an incline with an increase in tread force, a terrain travel, a standstill and a multiple shift can form the particular actual operating state.The target operating state may be at least one of a driver's wheel arch region and a pedaling force as a parameter. The pedaling force may include a minimum pedaling force and a maximum pedaling force. In this case, the pedaling force over a crank radius of a pedal crank can be provided as a pedaling torque as a parameter for a desired operating state. The driver's kade range may include a minimum kade and a maximum kade.The control device may be configured to set the transmission ratio of the drive unit such that a measured pedal force is less than a treading force. The control device may be configured to set the transmission ratio of the drive unit such that a measured carcass is within the driver carcass range.The control device can have at least one input interface for inputting parameters, for example parameters for the desired operating state, into the control device and an output interface for controlling the drive unit. The input interface may comprise an input device. For example, the input device may include at least one of a bicycle computer, a touchpad, a switch, or a lever. The deviation from the setpoint operating state can be legitimate by the driver via the input interface.The control device can have a computing unit. The computing unit can be designed such that it can execute a method for controlling the drive unit. The control device can have a data memory. The control device can have a location determination unit, for example a GPS module. The control device can have a data transmission unit, for example a Bluetooth, W-Lan or a mobile radio network module.In one embodiment, the control device for setting the transmission ratio of the drive unit taking into account the rotational speed gradient can be configured such that at least one parameter of the desired operating state is adjusted. The control device can be configured such that a parameter of the setpoint operating state is temporarily or temporarily adjusted for setting the transmission ratio, for example for the duration of a selected actual operating state or beyond. The control device can be configured such that a driver's cold zone is adapted. The control device can be configured such that the minimum kadence is reduced. The control device can be configured such that the maximum kadence is increased. The control device can be configured such that the pedaling force is adjusted. The control device can be configured such that the minimum pedaling force is reduced. As a result, the transmission ratio can be set in accordance with the situation in favor of high driving comfort. In this case, the transmission ratio can be set taking into account a driver's request that can be recognized by the control device.In one embodiment, the detection device can have a rotation angle reference element which is connected to the wheel in a rotationally fixed manner, and a rotation angle sensor for detecting the change in the rotation angle. The rotation angle sensor can be formed by a high-resolution rotation angle sensor which is configured to detect a change in the rotation angle with high resolution. The detection device can be configured to determine a relative rotation of the wheel to a bicycle frame.The rotation angle reference element may be linked or mounted to the wheel. The angle-of-rotation reference element can be connected or connectable indirectly, for example via a transmission stage, to the wheel in a rotationally fixed manner. The rotation angle reference element can be connected to an element of the drive unit, for example a sprocket, a chain, a crank or a motor shaft. The rotation angle reference element may be connected to a rim of the wheel. The rotation angle reference element can be connected to a wheel hub of the wheel. A change in the angle of rotation of the wheel can then be determined, for example, taking into account the actual transmission ratio of the drive unit.The angle-of-rotation reference element can be designed as a pulse disk. The rotation angle reference element may include detectable elements. The rotation angle reference element can have 360 detectable elements, for example. The detectable elements can be arranged uniformly distributed in the circumferential direction. One of the detectable elements can be formed by a sequence of at least two slits. The slots can be arranged one behind the other in the circumferential direction. The slotrs may overlap in a radial direction. The rotation angle reference member may extend circumferentially in a circumferential direction of the wheel. The rotation angle reference element can extend in sections in the circumferential direction.The rotation angle sensor may be linked to the bicycle frame. The rotational angle sensor can be configured such that, upon a rotation of the wheel, a detectable element is moved past the rotational angle sensor, so that the rotational angle sensor can detect the detectable element. The rotational angle sensor can be configured such that it generates a signal, for example an electrical signal, when one of the detectable elements is moved past the rotational angle sensor. The rotational angle sensor can be configured such that it generates an on-off signal when a plurality of detectable elements are guided past the rotational angle sensor one behind the other. At least one of the detection device and the control device can be configured to determine a wheel speed based on the signal of the rotational angle sensor. The rotation angle sensor may be formed by at least one of a Hall sensor, an inductive sensor, a light sensor, and an acoustic sensor.In one embodiment, the vehicle may include an acceleration sensor for detecting an acceleration of the vehicle as a parameter of the actual operating state.The acceleration may have a longitudinal acceleration in the direction of travel. The acceleration may have a lateral acceleration perpendicular to the longitudinal acceleration. The acceleration may have a normal acceleration perpendicular to the longitudinal acceleration and the lateral acceleration. The control device can be configured such that it can determine an inclination of the vehicle or an inclination of a roadway in the direction of travel movement taking into account an acceleration due to gravity. The control device can be configured such that it divides an inclination of the vehicle into classes during travel, for example into the classes level, low gradient, high gradient, low gradient, high gradient. The control device can be configured such that it divides the longitudinal acceleration during travel into classes, for example the classes standstill, acceleration low, acceleration high, deceleration low, deceleration high.The control device can be configured such that it determines an inclination of the vehicle via a torque balancing. For example, a residual torque can be determined via the crank torque, a prestored loss torque, which occurs, for example, due to friction losses in the drive unit and between the wheels and the roadway, and a wheel diameter. The control device can be configured such that it can determine the inclination via the residual torque, the vehicle mass and the wheel diameter. The control device can be configured such that it can determine a driving resistance based on wind-counter force via the residual torque.In one embodiment, the vehicle can have the crank for driving the drive unit with muscle power. The vehicle may include a crank sensor for detecting at least one of the crank torque, the pedal force, and the pedal of the crank as a parameter of the actual operating state. The pedal crank sensor can be formed by at least one of a torque sensor, a strain gauge or a pressure sensor.The control device can be configured such that it detects a change in gradient if a change in the wheel rotational speed or the rotational speed gradient is detected with the actual transmission ratio remaining the same. For example, a slope directed downward in the direction of travel movement, for example a negative slope or a gradient, can be detected if the wheel rotational speed increases or a positive rotational speed gradient is detected. For example, a slope directed upward in the direction of travel movement, for example a positive slope or a hill, can be detected if the wheel rotational speed is reduced or a negative rotational speed gradient is detected.As a result, the detection device can be configured such that it recognizes a condition of a ground. For example, a curbstone can be detected if a negative gradient, i.e. a negative rotational speed gradient, is first detected, for example, by a downward movement of a front wheel, and a positive gradient, i.e. a positive rotational speed gradient, is then detected, for example, by a downward movement of the rear wheel. Uneven terrain can be detected with corresponding changes in rotational speed gradient, for example with alternating occurrence of a positive and negative rotational speed gradient, with constant carcass.In one aspect, a method for controlling a drive unit for a vehicle according to one of the preceding specific embodiments includes ascertaining at least one parameter of a setpoint operating state. The method further comprises determining at least one parameter of an actual operating state. The method further includes determining a speed gradient of a wheel of the vehicle. The method further comprises setting a transmission ratio of the drive unit taking into account the rotational speed gradient, the at least one parameter of the desired operating state and the at least one parameter of the actual operating state.The method may include a step of changing a gear ratio or an assist level of the electric drive when the carcass leaves the driver carcass region. For example, a gear ratio of a lower gear may be set when the carcass is lower than a minimum carcass. For example, a gear ratio of a higher gear may be set when the carcass is higher than a maximum carcass. Here, a gear set based on the driver's wheel speed range and the wheel speed may constitute a theoretical gear. The method may include a step of setting a gear ratio of the drive unit that is different from the theoretical gear. The method can have a step in which the transmission ratio is optimized in a targeted manner by taking into account at least one of an output behavior, which comprises, for example, the wheel rotational speed and the rotational speed gradient, the inclination and the acceleration of the vehicle.In particular, the method can have a step in which the transmission ratio is optimized in a targeted manner in the particular actual operating states of full braking, slip, driving into a gradient, driving into a gradient with an increase in treading force, off-road travel, standstill and multiple shifting.In one embodiment, a parameter of the actual operating state may be formed by at least one of a wheel speed, a kadence, a pedal force, a crank torque, a vehicle acceleration, and an inclination of the vehicle.The actual operating state may include, as parameters, at least one of an actual gear ratio, a wheel speed of the wheel, a speed gradient of the wheel, a carcass, a crank torque, a pedal force, a vehicle acceleration, and an inclination of the vehicle.In one specific embodiment, a parameter of the setpoint operating state may be formed at least by one of a driver's pedal range, a pedaling torque, and a pedaling force.In one specific embodiment, the transmission ratio may be set by adapting the preset driver's wheel speed range if the rotational speed gradient exceeds or falls below a limit value. As a result, a temporary shift lock can be provided in one step.The method can have a step in which an actual transmission ratio is maintained when a clearly negative rotational speed gradient is detected. Such a clearly negative rotational speed gradient can occur, for example, during full braking. In this case, the wheel can lock and the wheel speed can drop to zero. The time during which no change of the actual transmission ratio is made can be determined by a presettable locking time. The method can have a step in which the vehicle behavior is evaluated during this locking time on the basis of the acceleration and a gear jump that is smaller than to the theoretical gear or even no change at all in the actual transmission ratio is carried out. During this blocking time, the minimum charge can be reduced at least temporarily.The method can have a step in which an actual transmission ratio is maintained when a clearly positive rotational speed gradient is detected. Such a clearly positive rotational speed gradient can occur in the event of a slip, for example when the drive wheel is spinning on ice. The time during which no change of the actual transmission ratio is made can be determined by a presettable locking time. The method can have a step in which the vehicle behavior is evaluated during this locking time on the basis of the acceleration and a gear jump that is smaller than to the theoretical gear or even no change at all in the actual transmission ratio is carried out. During this blocking time, the maximum carcass may be increased at least temporarily.In one embodiment, the setting of the gear ratio may be performed to match the preset driver's wheel speed range when an inclination is detected. The setting of the gear ratio may be performed by adjusting the preset driver's wheel speed range when a change in inclination is detected.The method can have a step in which a transmission ratio of a low gear is set when an entry into an inclination, i.e. an inclination of the vehicle, is detected. The magnitude of the transmission ratio can be optimized as a function of the rotational speed gradient and the vehicle acceleration. For example, a transmission ratio can be set in which a plurality of gears are skipped in a shifting process. In this case, the maximum carcass can be increased at least temporarily.The method can have a step in which the actual transmission ratio is maintained when a travel in a terrain, for example rough terrain, is detected on the basis of the acceleration of the vehicle and the rotational speed gradient. In this case, the maximum carcass can be increased at least temporarily. In this case, the minimum thickness can be reduced at least temporarily. In this case, a driver's cold zone can be enlarged at least temporarily. The driver's wheel arch range can be adjusted at least temporarily on the basis of at least one of the acceleration and a determined gradient.In one embodiment, the adjusting of the gear ratio may be performed to match the preset driver's wheel speed range when at least one of the crank torque and the pedal force exceeds a threshold. As a result, a temporary switching lock can be provided.The method can have a step in which an actual transmission ratio is maintained if an acceleration initiated by the driver, for example an increased pedaling force, is detected in combination with an incline or the entry into an incline. The actual transmission ratio can then be maintained in order to generate more driver power, for example by an at least temporary greater maximum coefficient. Depending on the vehicle acceleration, setting of the gear ratio of a higher gear may be performed with delay.Alternatively, a lower speed gear ratio may be performed earlier. In this case, the maximum carcass can be increased at least temporarily.The method can have a step in which a large change of an actual transmission ratio over a plurality of gears is carried out if a distinct acceleration initiated by the driver, for example an increased pedal force, is detected. For example, a shift to a higher gear can be carried out as a multiple shift in which individual gears are skipped. As a result, a time in a gear being driven can be increased. In this case, the maximum carcass can be increased at least temporarily. This can result in a smooth driving feeling. For example, for a starting vehicle operating at high assist level, a sixth gear ratio may first be set. Upon further acceleration of the vehicle, a transmission ratio of a ninth gear may be set. Upon further acceleration of the vehicle, a transmission ratio of an eleventh gear may be set. Upon further acceleration of the vehicle, the transmission ratio can subsequently be set via simple gearshifts without a gear jump.In one specific embodiment, the transmission ratio may be set by adapting the preset driver's wheel speed range if a wheel rotational speed falls below a limit value.The method can have a step in which the wheel rotational speed 0 falls below the limit value. If the limit value is undershot, the vehicle can be recognized as being at a standstill. The wheel speed 0 may be detected, for example, when the wheel sensor does not output a signal for a preset period of time. Then, a gear ratio for starting may be set. The gear ratio for starting may be set in consideration of a detected inclination of the vehicle and the driver's wheel speed range. In the case of a positive gradient, for example a hill approach, the transmission ratio of a lower gear can be set. In the case of a negative gradient, for example a driveway in a gradient, the transmission ratio of a higher gear can be set.The control device of the drive unit of the bicycle may be configured to be able to carry out a method according to any one of the preceding embodiments.Brief Description of the FiguresFIG. 1 shows a flow chart of a method for controlling a drive unit for a vehicle.Detailed Description of EmbodimentsFIG. 1 shows a flow chart of a method for controlling a drive unit for a vehicle, in the present case a bicycle. The vehicle has a drive unit, a control device, a detection device and a wheel, in the present case a rear drive wheel. The drive unit can be temporarily operated with muscle power and has an electric drive, an energy store, in the present case a rechargeable battery, and a mechanical drive, in the present case a crank unit with a crank. A transmission ratio of the drive unit can be adjusted via the control device. The drive unit has a number of gears, which are each associated with a transmission ratio of the drive unit. High gear is associated with a lower gear ratio than low gear. During a shifting process, the control device changes the transmission ratio of the drive unit. A gear change takes place in this case.The detection device is configured for high-resolution detection of a change in the angle of rotation. The detection device is configured to determine a rotational speed gradient of the wheel. The control device is configured to set the transmission ratio of the drive unit taking into account a setpoint operating state and an actual operating state. The target operating state comprises parameters which are predefined by a driver. The actual operating state comprises parameters which are determined on the vehicle during operation.The control device is furthermore configured to set the transmission ratio of the drive unit taking into account the rotational speed gradient. In this case, the control device adjusts at least one parameter of the desired operating state for specific actual operating states.Further details of the bicycle and method will be described below.The target operating state comprises as parameters a driver's pedal speed range and a pedal force. In this case, the pedal force can be provided via a crank radius of a pedal crank as a pedal torque as a parameter for a setpoint operating state. The driver's kade range includes a minimum kade and a maximum kade. During operation of the vehicle, a minimum value should not be undershot and a maximum value should not be exceeded, except in certain actual operating states. A rider can input the parameters for the desired operating state into the control device via an input device, in the present case a bicycle computer with input keys.The actual operating state includes, as parameters, an actual transmission ratio, a wheel speed of the wheel, a wheel speed, a pedal force, a crank torque, a vehicle acceleration, and an inclination of the vehicle.The wheel speed is determined by the detection device via a rotation angle reference element, which is connected to the wheel in a rotationally fixed manner, and a rotation angle sensor for detecting a change in the rotation angle. The rotation angle reference element is configured as a pulse disk which extends circumferentially and annularly in a circumferential direction of the wheel. The rotation angle reference element has detectable elements, which in the present case are formed by 359 slots, which are arranged uniformly distributed in the circumferential direction and overlap in the radial direction. The rotational angle sensor is formed by a Hall sensor and is connected to a bicycle frame in a rotationally fixed manner for detecting the slots on the bicycle. When one of the slits passes the rotation angle sensor, the rotation angle sensor generates a pulse signal. If a plurality of slots are guided past the rotation angle sensor one behind the other, the rotation speed sensor generates an on-off signal. If the rotational angle sensor delivers an on-off signal, a rotation of the wheel with a corresponding wheel speed is detected. The rotation is a relative rotation relative to the bicycle frame. Between two slots following one another in the circumferential direction, a wheel sector of a wheel circumference is formed. A rotational speed is determined for each wheel sector. During a rotation of the wheel, each of the wheel sectors is successively moved past the rotation angle sensor. For a complete wheel revolution, the detection device detects 360 rotational speeds.The speed gradient is determined from successive speeds. If successive rotational speeds of two successive wheel sectors are equal, the detection device determines the rotational speed gradient 0. If a rotational speed of a wheel sector is greater than a rotational speed of a subsequent wheel sector, the detection device determines a rotational speed gradient<0. Then, the wheel is accelerated or braked negatively relative to the bicycle frame. If a rotational speed of a wheel sector is less than a rotational speed of a subsequent wheel sector, the detection device determines a rotational speed gradient>0. Then, the wheel is positively accelerated relative to the bicycle frame. From the rotational speed gradient, a wheel speed is determined precisely for each individual wheel sector. In an alternative embodiment, a wheel speed for a plurality of wheel sectors is determined on the basis of an average value of rotational speeds of these wheel sectors.The carcass is determined by the detection device in the present case by the wheel speed and an actual transmission ratio of the drive unit. In an alternative embodiment, the carcass is determined via a rotational speed sensor which detects the rotational speed of the crank of the bicycle.The crank torque is determined by the detection device via a pressure sensor on a pedal on the crank, the crank radius and a crank position. Here, the pressure sensor detects a pedaling force of the driver as a pedal force.The vehicle acceleration and the inclination of the vehicle are determined by the detection device via an acceleration sensor. Here, the inclination of the vehicle refers to a traveling direction of the vehicle.The controller sets a gear ratio of the drive unit according to the following method. In a first step, the control device carries out a determination (I) of the parameters of a desired operating state. In a further step, the control device causes the parameters of the actual operating state to be determined (II). In a further step, the control device causes a determination (III) of the rotational speed gradient of the wheel of the vehicle. In a further step, the control unit carries out a setting (IV) of a transmission ratio of the drive unit taking into account the rotational speed gradient, the parameters of the desired operating state and the parameters of the actual operating state. The method is then carried out again.The detection device recognizes the determined actual operating states full braking, slip, entry into a gradient, entry into a gradient with an increase in tread force, off-road travel, standstill and multiple shift.The full braking is detected by the detection device for a large negative rotational speed gradient. In this case, the rotational speed is greatly reduced for successive wheel sectors. The rotational speed gradient falls below a negative limit value. Full braking is detected when the wheel is locked and the wheel speed changes to 0. For full braking, the control unit changes the minimum value to 0 and does not change an actual transmission ratio. This provides a temporary shift lock.The slip is detected by the detection device for a large positive rotational speed gradient. In this case, the rotational speed increases greatly for successive wheel sectors. The rotational speed gradient exceeds a positive limit value. For the slip, the control unit increases the maximum value and does not change or delay an actual transmission ratio. This provides a temporary shift lock.The retraction into a gradient is detected by the detection device when the rotational speed gradient increases slightly for successive wheel sectors and the acceleration sensor detects a corresponding change in the orientation of the gravitational acceleration with respect to the bicycle frame. For driving into an incline, in the present case a mountain trip, the control unit increases the maximum tooth rate. Starting from the actual transmission ratio, a transmission ratio of a lower gear is set prematurely. Depending on the height of the inclination, for example a class of the inclination, and the acceleration, for example a class of a longitudinal acceleration, of the vehicle, a multiple shift is carried out. A multiple shift changes the transmission ratio by the control device skipping one or more gears during the shifting process.The driving into a gradient with an increase in treading force is detected by the detection device if, in addition to the driving into a gradient, the detection device detects that a treading force of the driver exceeds a specific limit value over a pedal crank revolution. For the retraction into a gradient with an increase in tread force, the control unit increases the maximum kadence. Starting from the actual transmission ratio, a transmission ratio of a lower gear is set prematurely or a transmission ratio of a higher gear is set with a delay.Off-road travel is detected by the detection device when the rotational speed gradient alternately slightly increases and slightly decreases for successive wheel sectors and the acceleration sensor detects a corresponding change in the orientation of the gravitational acceleration with respect to the bicycle frame. For off-road travel, the control unit increases the maximum fence and reduces the minimum fence. This increases the driver's cold zone and reduces a number of shifts during off-road travel.A standstill of the vehicle is detected by the detection device if the rotational angle sensor does not generate a pulse signal for a specific period of time. For standstill, the control unit adjusts a transmission ratio of a corresponding gear depending on the detected inclination and the driver's wheel speed range. For standstill, the maximum kadence is increased.A multiple shift is detected by the detection device when a pedaling force of the driver exceeds a certain limit value over a crank revolution. For the multiple shift, the control unit increases the maximum cable. The controller changes the gear ratio by the controller skipping one or more gears in the shift. For example, starting from a transmission ratio of a sixth starting gear 6, firstly a 3-fold shift is set to a transmission ratio of a ninth gear, then a double shift is set to a transmission ratio of an eleventh gear and finally, via single shifts, the transmission ratio of the next higher gear is set.Reference numerals denote reference numeralsI Determining at least one parameter of a setpoint operating state II Determining at least one parameter of an actual operating state III Determining a rotational speed gradient of a wheel of the vehicle IV Setting a transmission ratio of the drive unit

Claims

Vehicle having a drive unit which can be operated with muscle power and has an adjustable transmission ratio, a control device for setting (IV) the transmission ratio of the drive unit and a detection device for high-resolution detection of a change in angle of rotation for determining (III) a rotational speed gradient of at least one wheel of the vehicle, wherein the control device is set up for setting (IV) the transmission ratio of the drive unit taking account of a setpoint operating state and an actual operating state, and the control device is set up for setting (IV) the transmission ratio of the drive unit taking account of the rotational speed gradient.Vehicle according to Claim 1, characterized in that the control device for setting (IV) the transmission ratio of the drive unit taking into account the rotational speed gradient is set up in such a way that at least one parameter of the setpoint operating state is adapted.Vehicle according to one of the preceding claims, characterized in that the detection device has a rotation angle reference element which is connected to the wheel in a rotationally fixed manner, and a rotation angle sensor for detecting the change in the rotation angle.Vehicle according to one of the preceding claims, characterized in that the vehicle has an acceleration sensor for detecting an acceleration of the vehicle as a parameter of the actual operating state.Vehicle according to one of the preceding claims, characterized in that the vehicle has a crank for driving the drive unit with muscle power, the vehicle has a crank sensor for detecting at least one of a crank torque, a pedal force and a pedal of the crank as a parameter of the actual operating state.Method for controlling a drive unit for a vehicle according to one of the preceding claims, wherein the method comprises - determining (I) at least one parameter of a setpoint operating state, - determining (II) at least one parameter of an actual operating state, - determining (III) a rotational speed gradient of a wheel of the vehicle, - setting (IV) a transmission ratio of the drive unit taking into account the rotational speed gradient, the at least one parameter of the setpoint operating state and the at least one parameter of the actual operating state.Method according to Claim 6, characterized in that a parameter of the actual operating state is formed at least by one of a wheel speed, a wheel speed, a pedal force, a crank torque, a vehicle acceleration and an inclination of the vehicle.Method according to Claim 7, characterized in that a parameter of the setpoint operating state is formed at least by one of a driver's wheel arch region, a pedaling torque and a pedaling force.Method according to Claim 8, characterized in that the transmission ratio is set (IV) by adapting the preset driver's wheel speed range if the rotational speed gradient exceeds or falls below a limit value.Method according to Claim 8 or 9, characterized in that the transmission ratio is set (IV) by adaptation from the preset driver's wheel speed range if an inclination is detected.Method according to one of Claims 8 to 10, characterized in that the transmission ratio is set (IV) by adaptation of the preset driver's wheel speed range if at least one of the crank torque and the pedal force exceeds a limit value.Method according to one of Claims 8 to 11, characterized in that the transmission ratio is set (IV) by adaptation of the preset driver's wheel speed range if a wheel rotational speed falls below a limit value.

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